In the Silo TV show, what is the purpose of this deception?

Question

Note: I haven't read any books in the Silo series, and I assume a show must be self-contained. However, it's possible the question I'm asking will be answered in Season 2 using material from the books. I'll accept an answer in that direction.

This question is about the displays in Silo.

In the Silo TV show, people live in some kind of underground bunker, the titular silo. They are told the world outside is inhospitable and poisonous, and that they must stay inside the silo or they will die. They can watch the world immediately outside the silo via several display screens, placed all across the silo and fed from a sensor at the top of it. The displays show a desolate, barren landscape, seemingly confirming the message that the world outside is dangerous and cannot sustain life.

However, some characters discover

secret images and videos showing the world outside is actually green and lush. So they believe they are being fed a lie, and some become rebellious because of this, or at least eager to find more details about this deception and possibly want to leave the silo. "Knowledge" of this "fact" is suppressed and severely punished by the silo authorities. When people are sent outside to "clean" and die, the world they see is indeed green and lush, so it would seem the barren landscape is a lie.

But then, even later in the show there's a further revelation:

The world outside actually is barren and poisonous. The video screens all over the silo are showing the truth, and the only lie is actually the display in the helmet of those sent outside to "clean" and die: it deceives them into believing the world outside is safe, and they want to show this to the people inside, which is why they end up cleaning the sensor before dying from breathing the poison or whatever.

Assuming this last sentence is the whole point of the deception:

That is, the purpose of the fake helmet display showing a healthy world is to encourage people sent outside to actually clean the sensor, which otherwise they might not do out of spite... Why is this double lie even necessary? In the show, people get sent outside mostly because they "learned" about this suppressed falsehood that the world outside is green and that the toxic world is a lie. But if the authorities were clear that the world is truly toxic, and didn't plant a tempting falsehood to begin with, people wouldn't want to leave the silo or rebel at all. So why is the "green world" lie even necessary? The reality of Silo matches what the authorities would want people to believe: that it's not safe to leave the silo. So wouldn't telling the truth at all times be simpler, instead of this convoluted double lie?

Did I misunderstand, and there is another purpose to the deception? Or will this apparent contradiction be answered in later seasons, if they follow the plot of the books (which I haven't read)?

Answer 1

Spoilers to follow for the novel series.

The starting point is the worldwide spread of hostile/potentially hostile nanotechnology. It's noted that any one threat can be countered, but eventually one will sneak past, and the psychological impact would be beyond even the physical threat. This is talked about in Shift.

‘I never saw a design with a hundred per cent efficiency,’ Erskine said. ‘We weren’t there yet with our own work, and everything from Iran and Syria was much cruder. Now, North Korea had some elegant designs. I had my money on them. What they had already built could’ve taken out most of us. That part’s true enough.’

I knew what they could do, how fast they could restructure themselves, evolve, if you will. Once it started, it would only stop when we were no longer around. And maybe not even then. Every defence would become a blueprint for the next attack. The air would choke with our invisible armies. There would be great clouds of them, mutating and fighting without need of a host. And once the public saw this and knew . . .’ He left the sentence unfinished.

‘Hysteria,’ Donald muttered.

The Silo project was intended as a reset for the world - both allowing the hostile nanotechnology to be neutralised, and also removing human knowledge of the worst of our existing technology.

Erskine glanced up at the ceiling. ‘The world outside isn’t just being scrubbed of humans right now, if that’s what you’re asking. It’s being reset. All of our experiments are being removed. By the grace of God, it’ll be a very long time indeed before we think to perform them again.’

The ultimate plan is to have a single silo repopulate the world - the one rated as having the best chance of success. This is dependant on keeping them all in the silos for the planned 500 years. The local damage that is maintained, and the visibility of this, is also intended to keep them in:

Donald realised how strange it was that they had a wall screen in silo one. The people here knew what they’d done to the world. Why did they need to see the ruin they’d left behind?

Unless—

Unless the purpose was the same as for the other silos. Unless it was to keep them from going outside, a haunting reminder that the planet was not safe for them.

Within each Silo, a small number of people (usually two) know the overall plan, but some of the necessary data is also stored in the servers, so in theory can be accessed - which means that ultimately some individuals start to question the received wisdom.

For those who do leave, the reasoning for cleaning is still a bit vague, but the viewpoint of Holden is given in the first novel:

Holston reached down and pulled a wool pad from his chest. The cleaning! He knew, in a dizzying rush, a torrent of awareness, why, why. Why!

[...]

And for him, it wasn’t the raw anger he imagined many might have cleaned with. It wasn’t the knowledge that they in the silo were condemned and the condemned set free; it wasn’t the feeling of betrayal that guided the wool in his hand in small, circular motions. It was pity. It was raw pity and unconstrained joy.

[...]

But no, there were appearances to keep, illusions to maintain. He wasn’t sure why, but it was what his wife had done, what all the other cleaners before him had done. Holston was now a member of that club, a member of the out group. There was a press of history, of precedent, to obey. They had known best. He would complete his performance for the in group he had just joined. He wasn’t sure why he was doing it, only that everyone before him had, and look at the secret they all shared. That secret was a powerful drug.